The Miami Dolphins always knew they would open the season without Kenneth Grant. What they learned Wednesday is that the calendar on his return is less settled than the transaction implied.
Grant, placed on injured reserve with a designation to return on Aug. 30, was on the practice field in a minor boot on his left foot, and head coach Jeff Hafley declined to say whether the 2025 first-round pick will be ready when he first becomes eligible in Week 5.
Hafley had already softened the timeline a day earlier. Asked Tuesday whether Grant had a good chance to return after four games, the coach gave an answer that stopped well short of a yes, according to the team’s official transcript.
“I’m hopeful. I was hoping that he wouldn’t have to go on the injured reserve. So I would say that I’m hopeful that he’ll be back, but we’ll see,” Hafley said.
That is the sound of a four-game absence becoming a minimum rather than a plan, and it lands 11 days before a season opener in Las Vegas that Miami will play with four interior defensive linemen on the 53-man roster.
What the boot changes
The Dolphins have never specified Grant’s injury beyond a lower-leg issue that surfaced in mid-August, and Wednesday’s boot is the first visible detail the new regime has allowed to reach the public. It does not answer the question of severity, but it does reframe the timeline.
A player on injured reserve with a return designation must sit at least four games, which puts Grant’s earliest possible activation at Week 5, and teams have eight regular-season activations to spend. Miami used two of its cutdown-day designations on Grant and rookie linebacker Trey Moore, so both count against that ledger whenever they are activated.
The first four games are the road trip to the Raiders on Sept. 13, a second straight West Coast date at the 49ers on Sept. 20 and the home opener against the Chiefs on Sept. 27, before a Week 4 game that closes the window. The full slate is on the Dolphin Nation schedule page.
If Hafley’s hedge holds, the stretch Grant misses could extend past a month of the season in which the front is already being asked to hold up against Kansas City’s interior.
How Miami got here
The decision to shelve Grant was telegraphed for a week. Hafley called the roster “thin still” on cutdown Saturday and acknowledged the IR-return discussions before the move became official, a sequence Dolphin Nation covered in detail at the time, including why the timing of the designation mattered and why Pro Football Focus had tagged Grant as a 2026 breakout candidate on the strength of his second-half improvement.
The short version is that the Dolphins chose the version of IR that preserves a midseason return rather than the one that ends the year, which only pays off if the injury cooperates.
Four linemen and a big end
The initial 53 carried exactly four interior defensive linemen: Zach Sieler, Zeek Biggers, Jordan Phillips and undrafted rookie Keith Cooper Jr. Sieler is the anchor, but he missed time himself during camp and sat out the preseason opener in Washington, which is part of why the room is being handled so carefully.
Miami added a fifth body on Monday when it signed Malik Herring, a veteran who spent four seasons in Kansas City, in the same churn that brought seven waiver claims onto the roster.
Hafley described Herring on Tuesday as a bigger end who can “play a 6-technique, reduce down, play a 9-technique and can be really strong against the run,” according to the transcript, which is coach-speak for a player who can slide inside on early downs without being a true tackle. That flexibility helps, but it does not replace a 326-pound nose.
Mazi Smith and the Michigan reunion
The more interesting insurance arrived Tuesday afternoon, when the Dolphins signed defensive lineman Mazi Smith to the practice squad as part of an eight-player wave that also included fellow interior lineman Jordan Miller, the team announced.
Smith was the No. 26 overall pick by the Cowboys in 2023, has appeared in 42 NFL games with 2.0 career sacks and is listed at 6-foot-3, 337 pounds. Dallas sent him to the Jets last November in the trade that brought Quinnen Williams to Texas, and New York released him at cutdowns.
The connection Dolphins fans will notice is the school. Smith played at Michigan from 2019 through 2022, and Grant arrived in Ann Arbor as a freshman in 2022, which means the two shared a defensive line room for Smith’s final college season.
Miami now has two former first-round Michigan tackles in the building, one in a boot and one on the practice squad, and the second is there in part because of the first. Miller, the other Tuesday addition, is a former Miami Hurricanes tackle who finished his college career at SMU.
Neither practice-squad lineman counts against the 53, which is the whole point: The Dolphins get two developmental bodies with size without cutting anyone to make room, and either can be elevated on a game week if the four-man group gets stretched.
What Grant’s absence actually costs
The honest answer is that it costs Miami a development window more than a proven starter. Grant played all 17 games as a rookie with five starts, finishing with 33 tackles, 2.0 sacks and five quarterback hits on 554 defensive snaps, or 52 percent of the team’s total.
Pro Football Focus graded him at 48.4 for the season, 107th among 134 qualifying interior linemen. Those are not numbers a defense collapses without. What the Dolphins lose is the second-year jump they were counting on from the 22-year-old, and the reps that were supposed to produce it.
Every week Grant spends in a boot is a week Cooper and Biggers absorb snaps that were penciled in for him, and the longer the timeline stretches past Week 5, the more the practice-squad signings start to look like a hedge against the season rather than against a month.
What comes next
Hafley said the players will vote on captains later this week, and he plans to name them either Thursday or after the team returns from Las Vegas. The Dolphins open at the Raiders on Sept. 13 at 4:25 p.m. ET on FOX.
Grant was not the only injury note from Wednesday. Tight end Will Kacmarek did not practice and Seydou Traore appeared limited, while linebacker Ronnie Harrison Jr. worked on the side and newcomers Ollie Gordon II and Reese Taylor wore red non-contact jerseys.
The first official injury report of the regular season arrives next week, and it will be the first time the Dolphins are required to put a designation next to any of those names.
